Friction shock absorbing mechanism



Nov. 1, 1949. G. E. DATH FRICTION SHOCK ABSORBING MECHANISM 2 Sheets-Sheet 1 Filed Feb; 5, 1945 v lrweni'ar Geaz geif flat/L wry G. E. DATH FRICTION SHOCK ABSORBING MECHANISM Nov. 1, 1949.

2 Sheets-Sheet 2 Filed Feb. 5, 1945 Patented Nov. 1, 1949 FRICTION S K ABS BI G MECHANISM George ;E. Path .Mokena, 'IlL, assignor to W. H. Miner, In Chi ago, BL, a corporat on of :Delaware Application February 5, 1945, Serial No. 576,166

9 Claims. 1

This invention relates to improvements in friction shock absorbing mechanisms for draft riggings of railway cars.

Qne object of the invention is to provide a friction shock absorbing mechanism havin preliminary spring action during partial compression of the mechanism to absorb the lighter shocks to which the same is subjected, and high frictional resistance to absorb the heavier shocks wherein the high frictional resistance is produced by relatively movable friction elements which become operativeafter said partial compression has :been effected.

A m r s ecifi o j ct of the inv ntion is. t provides mechanism as set for h in the p ecedin paragraph, wherein the relatively movable friction elements in lude a column nd a sprin re. sisted friction clutch Slidable len thwise on sai column, the clutch including friction shoes which eceive the actuatin force and a combined wed e and sprin follower with which the sh es have wedging en agement after predetermined partial compression of the mechanism, the friction shoes being held projected outwardly away from the combined wed e and sprin follower the non mal full release position of the mechanism by spr n m ans which provides the pr liminary spring action by compression thereof whil he sh es are being moved toward the com in d wedge and spring follower.

.Qther objects of the invention will more clearly appear from the description and claims herein after following,

In the drawings formin a par of thi spe ification, Fi u e 1 is a fron lev tional view of my improved friction shock absorbing mechanism. Figure .2 is a longitudinal, vertical sectional view, correspondin substantially to the line 27-2 f Eigure '1. Figure 3 is a transverse, vertical sectional view, correspondin substantially o he lin 3,.,;3 of Figure 2. Figure e is a front elevational view of the wed e emp oy d in y improved mechanism. Fi ure 5 is a rear elevational view of one-of the friction shoes employed in my improved mechanism. Figure ,6 is a view, similar to Figure 1, illustrating another embodiment of the invention. Figure 7 is a longitudinal, vertical sectional view, corresponding substantially to the line '!.-"i of Figure .6. Figure B is a transverse, vertical sectional view, corresponding substantially to the line 8.:8 of Figure .7.

Referring first to the embodiment of the invene tion illustrated in Figures 1 to 5 inclusive, my improved friction shock absorbing mechanism comprises broadly a friction casing A; a wedge block 2 3; three friction shoes C-.-C..-C; a main spring resistance comprising inner and outer coil springs D and E; a preliminary spring F; and a retainer bolt G.

The casing A is in the form of a tubular mem ber of hexagonal, transverse cross section, open at its front end and closed at itsrear end by a transverse, vertical wall to. The wall It is extended laterally outwardly of the casing A at opposite sides thereof, thereby providing flanges l I 0. In which form a rear follower member integral with the casing. At the forward end, the walls of the casing are thickened, thereby providing the friction shell section proper l l, which is of hexagonal, interior cross section. The interior walls of the friction shell section present three interior friction surfaces l-2-.-I2l2 which converge rearwardly of the mechanism and are of V- shaped, transverse cross section, each surface being formed by two adjacent walls of the shell. The opening at the front end of the casing, which opening is indicated by l3, is of true circular formation and the inner faces of the walls of the friction shell section of the casing, ered in transverse direction, are tangent to the circle defining said opening. Inturned flanges l4l4l4 at the forward or open end of the casing define the circular opening l3, having their inner edge faces curved, each flange extending from the mid portion of one face to the mid por= tion of the other face of each V-shaped friction surface l2. These flanges l4l4 |d form stop shoulders at alternate corners of the casin that is, a stop shoulder at the apex of each /-shaped fric ion surfa e he stop shoulders formed by the flanges ll4-l4 serve to limit movement of the friction shoes ,C-e-C-C outwardly of the casing A.

The wedge B comprises a block in the form of a t un d p r mid of hexagona shape, aresenting three forwardly converging wedge faces [5-4 5-915 of V-shaped, transverse cross section, each Vl-shaped wedge face being formed by two adjacent sides of the hexagonal block. The block B has a transverse, flat, front end face It on which the rear end of the preliminary spring F hears, and-a transverse, flat, rear end face ll on which the front end of the spring E bears. A rearwardly opening central pocket It is provided in the block 15, forming a seat for the front end f the sprin D.

To prevent rotation of the block B within the casing A, the former is provided with two diametrically opposite, radial wings or lugs lt-e-lii k which engage within diametrically opposite corners of the hexagonal casing A.

The friction shoes C, which are three in number, are of like design and arranged symmetrically about the longitudinal central axis of the mechanism. Each shoe C is of generally V-shaped, transverse cross section and has a longitudinally extending friction surface 20 of V-shaped, transverse cross section on its outer side at the rear end portion thereof, slidably engaging the corresponding V-shaped friction surface l2 of the casing. Forwardly of the friction surface 20, the outer side of each shoe is inwardly offset, as indicated at 2|, the surface of said offset portion being transversely curved, thereby providing the offset section 2| with a rounded outer side. The curved surfaces of the sections 2|2l-2l of the three shoes are of the same radius and lie in a circle which is concentric with the circular opening l3 of the casing, but of slightly smaller diameter. The reduced front end portions of the shoes CC-C are thus freely movable inwardly and outwardly of the casing and guided in the opening 13. The offset sections 2| of the shoes provide transverse abutment shoulders 22-22-42 at the front ends of the friction surfaces adapted to engage in back of the flanges M of the casing A to limit outward movement of the shoes. At the forward end, each shoe is provided with an inturned flange 23 having laterally inwardly converging side edges which are radial to the longitudinal central axis of the mechanism. The flanges 23 of the three shoes are in abutment with each other along their radial side edges, the assembled shoes thus forming, in effect, a three piece cap divided on radial lines and having a flat front end wall which is formed by the three flanges of the shoes. An inwardly proj ectlng, central, spring centering boss 24 for the spring F is provided on the shoes C-CC, the boss being formed partly on each shoe. At the extreme rear end thereof, each shoe C has a wedge face 25 of V-shaped, transverse section on the inner side thereof, which is correspondingly inclined to and adapted to be engaged by the V-shaped wedge face I 5 at the corresponding side of the wedge block B.

As shown most clearly in Figure 2, the shoes C--CC are cut away at an inclination along their inner side edges, that is, the opposed inner edges of adjacent shoes diverge rearwardly of the mechanism, thereby providing a certain amount of clearance between the shoes at the rear end portions thereof to permit contracting the assembled unit of three shoes to allow insertion of the same within the friction casing through the open front end of the latter, as hereinafter described.

The main spring resistance comprising the coil springs D and E is disposed within the casing A, being interposed between the rear end of the Wedge B and the transverse end wall IQ of the casing, the spring E surrounding the spring D. The spring D is lighter and of less capacity than the spring E and has its front end engaged within the pocket [8 of the block B. The rear end of the spring D bears on an inwardly projecting, hollow boss 26 on the wall ID of the casing. The spring E has its front and rear ends bearing respectively on the flat rear end face ll of the wedge block B and the end wall ID of the casing.

The retainer bolt G extends through the inner coil D of the main spring resistance and has a head 21 at its front end seated in a pocket 28 in the wedge block B. At the rear end of the bolt G, a nut 29 is provided, which is disposed within the hollow boss 26 and has shouldered engagement therewith to anchor the bolt to said boss. The bolt G limits outward movement of the wedge block B, holding the same spaced inwardly from the shoes, in the normal full release position of the mechanism, and is preferably so adjusted that the springs D and E are under initial compression.

The preliminary spring F, which is relatively short, is embraced between the shoes CCC and has its front and rear ends bearing respectively on the flanges 23 of the shoes and the flat front end face it of the wedge block.

In assembling the mechanism, the spring F and the shoes CC-C are applied to the casing after the springs D and E and the wedge block B have been assembled therewith and the wedge block anchored by the bolt G. In applying the spring F and the shoes C--CC, the spring is first placed on top of the wedge block B while the casing is supported in vertical position. The shoes are then successively inserted within the casing A and the shoulders 22 thereof engaged in back of the flanges M-I4l4 of the casing, the clearance provided between the shoes at the rearend portions thereof permitting the necessary tilting to clear the flanges as the shoes are inserted.

The operation of my improved friction shock absorbing mechanism, as shown in Figures 1 to 5 inclusive, is as follows: Upon compression of the mechanism in the usual manner, the shoes CCC are forced inwardly of the casing against the resistance of the spring F, the latter being compressed against the wedge block B which is held substantially stationary during the first part of the compression stroke due to the high capacity of the main spring resistance comprising the springs D and E. During compression of the spring F, there is substantially no frictional resistance produced between the friction shoes and the friction surfaces of the casing A as the wedge faces of the shoes are not in contact with the wedge faces of the wedge block B at this time. A light preliminary spring action is thus provided to absorb the lighter shocks. As the shoes move inwardly of the casing during full compression of the mechanism, the wedge faces of the shoes come into engagement with the wedge faces of the block B, forcing the block B inwardly against the resistance of the main spring and wedging the shoes apart into tight frictional engagement with the friction surfaces of the casing. High frictional resistance is thus provided during the remainder of the compression stroke. When the actuating force is reduced, the main spring resistance comprising the springs D and E returns the wedge block B to the normal full release position shown in Figure 2 and the spring F returns the shoes to their full release position, the latter being limited in their outward movement by shouldered engagement with the stop flanges M-M-l4 of the casing. As shown in Figure 2, in the normal position of the parts, the wedge faces of the shoes and wedge block are spaced an appreciable distance apart, the retainer bolt G restricting outward movement of the Wedge to produce this result.

Referring next to the embodiment of the invention illustrated in Figures 6, '7, and 8, my improved friction shock absorbing mechanism, comprises a friction casing H; a wedge block J; three friction shoes KKK; springs L and M; and a retainer bolt N.

The casing H is in the form of a hollow, tubular member having a vertical transverse rear end wall 3! and is open at the front end. The front end si 'iilse ion ill h es nts 91 ii m l hea ing interio til-.32??? 9i v-shap d t nsve se p ess sect on whi h s aver e inwa d y the ea in .At the o en 1 .12.? I I h i iie eofi'ie e sii ei e ir ttien e sin ha a plural ty 9 izitiimesi flanges :5 :3 sim la to th fl n es Mm 41: 4 hers.- iiih e e c h si pmec io w th the s n es:-

a s mi i i iiize Th ed J s in the p ii pf e be w bl ak having a reduced front end portionfii! the form f nhale e e i te ra th rewith- .The ma hosi po i n o th Wed e J ifs-pr videdwi h fec s ii :35:35 w o ged smmet ti 1. 1. ab ut th lon i udinal vent al ax s o th JQIQQR- The We e a e 3 a e-o vhap s transie cre ts se and t th ee wed e iae s qnve e ip wanile the .mee e m- T e i tion hees K a e th ee nu be a hav io surfa 3K6 on the ou e si e there- Q h eh ex e d eng hw s o the me hanism and a o i -sh ed t a e e ss s c onfIhe V-shaped friction surface 35 of e aph shoe lid e en a e t e i noiisl v shane i fr n su ace 32 9 th fr t on shel o the casi The .shees K are P 9 i with in i iirned fla es 31 t th orwa d thene r n-s ngi t t e i on 13 ii he s es here: inbei le sr. bedi ohnectimi l i$ .1 i9 I Q HSWQ- A th rea end the shees a e Kid-.QQ wi h rat rall iiine cl .e ienqin telai. sly heavy flan s \3.8'8 wh h hreseni v sha es w s e i i9 11 the inn-er sii s thereei ada e o be ngaged by $1. We ge fa es .3 oi t e bipe J an q re pqndi sl inc in e eto. The rear enci portions of the shoes are cut away at opposite sides to provigle clearance to permit tilting of the shoes in a manner similar g to the shoes C -C--C to facilitate the assembling operation, as herein-bef ore ;lescrioed in connection with Figures 1 to 5 inclusive. Forwargly of the V-shaped fr-icton suriace 35, each shoe K has a shoulder similar to the shoulder 22 of the shoe C helical coil which surrounds the spring M and d i tti svexs ei ssesiien Iheiiict en e es 1 i ine usi e a d inner-stin bears at its front and rear ends .onthe inner ends of the shoes and transverse .end wall -38 of the casing, respectively.

The spring M, which is in the form of .a mela: tively light inner coil, bears .on the rear end of the Wedge J and the Wall of the casing and is c nter d n an inwar pro ectin holiow 1119.55 4m- .,extend. ne f om the wall 13.!)-

The wise b ck J is an h -51 o the easing by the retain r lt N, nevi-nee head at it ea end should ed w thin the ho low bos Al and a no at ts iit n e si in shoulfleree en ment with he We e bl c J- Th l s li N h lds th ed e b.199 i 1 es iion with he weiie :ise 55 ther o spaced r a -wa ms ein the Wed .38 o e shoes a st e earlv i lustra ed 7. we '7, which skew th norm position o th pa ts- The o eration o the ie eie es $29M? F $E 5 @2 ii 9 19W PM?" e iee fiss es e the a. st the res tame 9 th is M I? ring t i a t n the apa t th Wed e .J .i9

ti 4 ii sw ms of the gas; g as -e shoes sl de rea Wandly of the easin th eby emvid i hie'h f ictio a sis a ee iiii ine last a o t e compression h i ee ne this ae eii h heavy coil sprin a so s eni res ec thii dd n t the eaee ity o the net-i e, the actuat ng force i redueegi, the springs 1 and M return all of the arts to the nprnial full release position shown in? use newer-s moveme f t hoe bein lim by iil ere eas men it h n es 3.3 @i the e is and en ia si m vement th wise ein l m te evil-1e reta ner o 7N- elaim i. a r iph ehsorhioe the ombi iamen w th a i ini c sin havin lengthwise extending, interior ct n suri ages; 9i irietipn shoes eiesc iied W e casi n thw se slid n en a e sa ri tion sai sh e 9 er iee iie it- @w div beyond th end o h c sin t re iv the enlistin ieree; a ombined wed e a shr ne isili pwer mem e said mem er an sh s avin we ge vi ee s en 'eee i h eac t er afte saiel niee isni has been Pa all mresse i a, s 'yie di iely o posin m veme t e ai s ee inw rdl f t e ca n a s nd s rin e eiin iy opp sin movem o saici nm ed wed e and r n f w m mbe oi h asin o r e tin out ari m vement of id sh s d means ior a est i is o twersi m emen i aid eomb d we e ahsi n ins ellgw mem er i eosi iq w h the W d e th eo in i wa s d e on sp et to the e e vf c o h s e t e. inwa m em nt o sai h e wit re Jane i, to he win-b ed ii and spring o s d r n saisi sert a som es n o e mec a- .In ii 1. shock ab in m han sm, the 91m at Ii w th a .friction s n havin p iit ier in n urf e extending l n thw e therepi; of lotion shoes telescoped within the seei g le gth i e iisi ne enseem i h d friction surfaee s, said shoes normally projecting ontwarqly beyond the end .of the casing to receive th ac uat ng r-ce n d Wedg d ng ieiip e memb r w th said a n sai mem er he s ha in wedg faces e sage b ith ea h et er a te aid m eh iii as e n e tially eomp s e a spring buttresse a it iroiii wedge faces thereof in inwardly spaced relation with the wedge faces of said shoes to permit inward movement of said shoes with respect to said member during partial compression of the mechanism.

3. In a friction shock absorbing mechanism, the combination with a friction casing having interior friction surfaces extending lengthwise thereof; of friction shoes telescoped within the casing in lengthwise sliding engagement with said friction surfaces, said shoes normally projecting outwardly beyond the end of the casing to receive the actuating force; a combined wedge and spring follower member within said casing, said member and shoes having wedge faces engageable with each other after said mechanism has been partially compressed; a spring interposed between said shoes and member and bearing at its front and rear ends respectively against said shoes and member to yieldingly oppose movement of said shoes inwardly of the casing; a second spring buttressed at its front and rear ends respectively against said member and casing to yieldingly oppose movement of said member inwardly of the casing; means for arresting outward movement of said shoes; and means for arresting outward movement of said member in position with the wedge faces thereof in inwardly spaced relation with the wedge faces of said shoes to permit inward movement of said shoes with respect to said member during partial compression of the mechanism.

4. In a friction shock absorbing mechanism, the combination with a friction casing open at its front end and closed at the rear end, said casing having inturned stop flanges at its open end and lengthwise extending, interior friction surfaces at said open end inwardly of said stop flanges; of friction shoes telescoped within the casing in lengthwise sliding engagement with said friction surfaces, said shoes having shoul- 'dered engagement with said stop flanges to arrest outward movement of said shoes with the outer ends of the shoes projecting from the casing to receive the actuating force; a combined wedge and spring follower member rearwardly of the shoes, said member and shoes having wedge faces engageable with each other after said mechanism. has been partially compressed; a spring yieldingly opposing movement of said shoes inwardiy of the casing; a second spring yieldingly opposing movement of said member inwardly of the casing; and a retainer bolt anchored at its opposite ends to said member and casing for arresting outward movement of said member in position with the wedge faces thereof in inwardly spaced relation with respect to the wedge faces of said shoes to permit inward movement of said shoes with respect to said member during said partial compression of the mechanism.

5. In a friction shock absorbing mechanism, the combination with a friction casing open at its front end and closed at the rear end, said casing having inturned stop flanges at its open end and lengthwise extending, interior friction surfaces at said open end inwardly of said stop flanges; of friction shoes telescoped within the casing in lengthwise sliding engagement with said friction surfaces, said shoes having shouldered engagement with said stop flanges to arrest outward movement of said shoes with the outer ends of the shoes projecting from the casing to receive the actuating force; a combined wedge and spring follower member within said casing rearwardly of the shoes, said member and shoes having wedge faces engageable with each other after said mechanism has been partially compressed; a spring buttressed at its front and rear ends respectively against said shoes and closed end of the casing yieldingly opposing movement of said shoes inwardly of the casing; a second spring buttressed at its front and rear ends respectively against said member and closed end of the casing yieldingly opposing movement of said member inwardly of the casing; and a retainer bolt anchored at its opposite ends to said member and casing for arresting outward movement of said member in position with the wedge faces thereof in inwardly spaced relation with respect to the wedge faces of said shoes to permit inward movement of said shoes with respect to said member during said partial compression of the mechanism.

6. In a friction shock absorbing mechanism, the combination with a friction casing open at its front end and closed at the rear end, said casing having inturned stop flanges at its open end and lengthwise extending, interior friction surfaces at said open end inwardly of said stop flanges; of friction shoes telescoped within the casing in lengthwise sliding engagement with said friction surfaces, said shoes having shouldered engagement with said stop flanges to arrest outward movement of said shoes with the outer ends of said shoes projecting from the casing to receive the actuating force; a combined wedge and spring follower member within said casing rearwardly of the shoes, said member and shoes having wedge faces engageable with each other after said mechanism has been partially compressed; a spring interposed between said shoes and member and bearing at its front and rear ends respectively against said shoes and said member, and yieldingly opposing movement of said shoes inwardly of the casing; a second spring buttressed at its front and rear ends respectively against said member and closed end of the casing and yieldingly opposing movement of said member inwardly of the casing; and a retainer bolt anchored at its opposite ends to said member and casing for arresting outward movement of said member in position with the wedge faces thereof in inwardly spaced relation with respect to the wedge faces of said shoes to permit inward movement of said shoes with respect to said member during said partial compression of the mechanism.

7. In a friction shock absorbing mechanism, the combination with a column element having lengthwise extending friction surfaces; of friction shoes in lengthwise sliding engagement with said friction surfaces, said shoes normally projecting outwardly beyond the end of said column element to receive the actuating force; a combined wedge and spring follower member, said member and shoes having wedge faces engageable with each other after said mechanism has been partially compressed; spring means yieldingly opposing movement of said shoes inwardly of said element; a second spring means yieldingly opposing movement of said combined wedge and spring follower member inwardly of said element; means for arresting outward movement of said shoes; and means for arresting outward movement of said combined wedge and spring follower member in position with the wedge faces thereof in inwardly spaced relation with respect to the wedge faces of the shoes to permit inward movement of said shoes with respect to the combined wedge and spring follower during said partial compression of the mechanism.

8. In a friction shock absorbing mechanism, the combination with a column element having interior friction surfaces extending lengthwise thereof; of friction shoes in lengthwise sliding engagement with said friction surfaces, said shoes receiving the actuating force; a combined wedge and spring follower member rearwardly of said shoes, said member and shoes having wedge faces engageable with each other after said mechanism has been partially compressed; a spring buttressed at its front and rear ends respectively against said shoes and column element to yieldingly oppose movement of said shoes inwardly of said element; a second spring buttressed at its front and rear ends respectively against said member and column element to yieldingly oppose movement of said member inwardly of said element; means for arresting outward movement of said shoes, with the outer ends thereof projecting outwardly of said element to receive the actuating force; and means for arresting outward movement of said member in position with the wedge faces thereof in inwardly spaced relation ment with said friction surfaces; a combined wedge and spring follower member rearwardly of said shoes, said member and shoes having wedge faces engageable with each other after said mechanism has been partially compressed; a spring interposed between said shoes and memher and bearing at its front and rear ends respectively against said shoes and member to yieldingly oppose movement of said shoes inwardly of said element; a second spring buttressed at its front and rear ends respectively against said member and said element to yieldingly oppose movement of said member inwardly of said element; means for arresting outward movement of said shoes with the outer ends thereof projecting beyond the outer end of said element to receive the actuating force; and means for arresting outward movement of said member in position with the wedge faces thereof in inwardly spaced relation with the wedge faces of said shoes to permit inward movement of said shoes with respect to said member during partial compression of the mechanism.

GEORGE E. DATH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,175,580 Anderson Mar. 14, 1916 2,329,338 Dath Sept. 14, 1943 

